Shotgun sequencing of activated sludge microcosm: enrichment culture
High-quality genomic DNA was extracted from cells using a Qiagen Genomic-tip (QIAGEN) according to the manufacturers instructions; purity and concentration of isolated genomic DNA was determined by Nanodrop.  Shotgun metagenomic sequencing was performed on an Illumina HiSeq platform (NovogeneAIT Genomics Singapore Pte, Singapore).